Hmm... should be working... I would say your Hardware->Troubleshooting issue is definitely related...

Have you tried re-installing the FTDI driver? The driver is at /System/Library/Extensions/FTDIUSBSerialDriver.kext . Deleting that file and rebooting seems to be the easiest way to remove the driver. The newest driver version is 2.2.10 and can be downloaded at http://www.ftdichip.com/Drivers/VCP.htm

I'm using the 2.2.9 version of the FTDI driver which came with Arduino with no problems, but I have an older Core1/32bit Macbook.

Once you get this straightened out, check out http://www.arduino.cc/playground/Interfacing/Cocoa . I wrote the IOKit/ioctl part, which lets you ramp up the baud-rate. You probably want the latest HardwareSerial(otherwise your Arduino can only hit 1000000 baud). http://code.google.com/p/arduino/source/browse/branches/processing-5503/hardware/cores/arduino/HardwareSerial.cpp?spec=svn702&r=702

Wow... I really don't have a clue... you've tried pretty much everything

The only thing I can come up with is maybe the CREAD flag on the termios structure for the serial-port is getting turned off by some misbehaving application. Most apps reuse the termios setting from the last application and only change the normal flags (databit size, parity, etc). The CREAD setting disables the serial port's reciever, so nobody changes it.

Thank you, gabebear for all your help. Unfortunately the Project you send didn't work either. :-/I selected the right Serial port and Baud Rate. The Arduino then Resetted and got frozen. It seems I'll have to keep using Windows for now... maybe on 00017 it will work? ;)

It definitely seems like driver problems to me, but I'm guessing the problem is with 10.5.7 Mac OS X and not with the Macbook itself. I might be wrong, but I think if it was the Macbook (hardware issue) it wouldn't work in the Windows trough the Virtual Machine. Am I right?

Besides that, I'm having the exact same problem (can write, can't read) with the Macbook and with an PL2303 USB/Serial cable using the open source driver. An FTDI USB/Serial cable from a friend works perfectly..

Well, lots of people are using 10.5.7 without issue, so it seems like it is something with that model...

Apple will sometimes ship beta-ish OS builds with their newest hardware. What is the build version of the Leopard that came with your laptop? You can check this in System-Profiler by clicking on the "Software" subcategory(not an item in it).

Mine is 9J61, which was displayed as "Mac OS X 10.5.7 (9J61)". It looks like the Macbook Pros made after June use build 9J3050. If both of you have this build, then I'd say it's a kext(kernel extension) problem and FTDI and Apple would like to know about it.

Here's the console output:avrdude: Version 5.4-arduino, compiled on Oct 9 2007 at 11:20:31 url line removed

System wide configuration file is "hardware/tools/avr/etc/avrdude.conf" User configuration file is "/Users/MYUSERNAME/.avrduderc" User configuration file does not exist or is not a regular file, skipping

How can I tell more specifically which board I have besides a Arduino Duemilanove AtMega328?

Also, I'm a step behind you guys, I can't even get a valid port name in the tools -> serial port menu to appear. I've tested Arduino-0016, FTDI driver(s) 2.2.9 and 2.2.10 on a 15" macbook pro, 13" macbook pro, 13" macbook, and a Mac Pro. None of them can even see the driver to select.

Furthermore, I can get it working fine using VMware (both XP and Kubuntu) on any of these platforms.

I have a new Mac mini (Core2 2Ghz, Nvidia9400M) with 10.5.7, fully updated. I use it as a media frontend for my TV. I just installed Arduino 16 and the FTDI 2.2.9 driver that comes with it. Everything worked perfectly, I uploaded a sketch and communicated with my Duemilanove.

I'm wondering if the FTDI chip on your Duemilanove is different(maybe a cheap Chinese clone). Open System Profiler, go to the USB section, and find the FTDI chip.

If you pull the 328p off the Duemilanove you are basically left with a FTDI adapter. Once you have removed the 328p, you can do a loopback test by connecting Pin0(RX) and Pin1(TX) and sending data to the serial port. Any data you send should come right back.

This device works fine on windows and linux boxes, but doesn't work on any mac machine for me. Whats even weirder is that I got it to work one time on my macbook, but once I rebooted the macbook, it's never worked again...

First thing we need to do is to alert the seller that he is selling boards that don't work on OSX with the regular FTDI driver... I'm almost certain he got his hands on a bad batch of FT232RL chips. If he can't rectify the problem then FTDI would probably like to know about this.

If the Arduinos shipped to you guys via China, there is a good chance the chips used to make your Arduinos are counterfeit. I recently got an oscilloscope from China with a Hoitek serial chipset ( http://www.hoitek.com/ ) . The USB Vendor ID in that chipset was stolen from Maxim ( http://www.maxim-ic.com/ ), but I'm not certain where the chip design is from. Hoitek seems to make knock-offs of some Atmel chips http://www.hoitek.com/PDF/8952.pdf .